CVE-2022-49769
Estado: AnalizadaMedia (5.5)—
In the Linux kernel, the following vulnerability has been resolved:
gfs2: Check sb_bsize_shift after reading superblock
Fuzzers like to scribble over sb_bsize_shift but in reality it's very unlikely that this field would be corrupted on its own. Nevertheless it should be checked to avoid the possibility of messy mount errors due to bad calculations. It's always a fixed value based on the block size so we can just check that it's the expected value.
Tested with:
Before this patch we get a withdraw after
and with UBSAN configured we also get complaints like
After the patch, these complaints don't appear, mount fails immediately and we get an explanation in dmesg.
Detalles técnicos trazas, registros y código del informe original
mkfs.gfs2 -O -p lock_nolock /dev/vdb
for i in 0 -1 64 65 32 33; do
gfs2_edit -p sb field sb_bsize_shift $i /dev/vdb
mount /dev/vdb /mnt/test && umount /mnt/test
done
[ 76.413681] gfs2: fsid=loop0.0: fatal: invalid metadata block
[ 76.413681] bh = 19 (type: exp=5, found=4)
[ 76.413681] function = gfs2_meta_buffer, file = fs/gfs2/meta_io.c, line = 492
[ 76.373395] UBSAN: shift-out-of-bounds in fs/gfs2/ops_fstype.c:295:19
[ 76.373815] shift exponent 4294967287 is too large for 64-bit type 'long unsigned int'CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 5.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.22%
- Percentil entre todas las CVEs puntuadas: 11
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- NVD-CWE-noinfo
Referencias
- https://git.kernel.org/stable/c/15c83fa0fd659dd9fbdc940a560b61236e876a80
- https://git.kernel.org/stable/c/16670534c7cff1acd918a6a5ec751b14e7436b76
- https://git.kernel.org/stable/c/1ad197097343568066a8ffaa27ee7d0ae6d9f476
- https://git.kernel.org/stable/c/28275a7c84d21c55ab3282d897f284d8d527173c
- https://git.kernel.org/stable/c/5fa30be7ba81191b0a0c7239a89befc0c94286d5
- https://git.kernel.org/stable/c/670f8ce56dd0632dc29a0322e188cc73ce3c6b92
- https://git.kernel.org/stable/c/8b6534c9ae9dba5489703a19d8ba6c8f2cfa33c2
- https://git.kernel.org/stable/c/d6b1e8ea6f3418c3b461ad5a35cdc93c996b2c87
JSON original (NVD)
Mostrar
{
"id": "CVE-2022-49769",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 5.5,
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 1.8
}
]
},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "b3b94faa5fe5968827ba0640ee9fba4b3e7f736e",
"lessThan": "d6b1e8ea6f3418c3b461ad5a35cdc93c996b2c87",
"versionType": "git"
},
{
"status": "affected",
"version": "b3b94faa5fe5968827ba0640ee9fba4b3e7f736e",
"lessThan": "1ad197097343568066a8ffaa27ee7d0ae6d9f476",
"versionType": "git"
},
{
"status": "affected",
"version": "b3b94faa5fe5968827ba0640ee9fba4b3e7f736e",
"lessThan": "15c83fa0fd659dd9fbdc940a560b61236e876a80",
"versionType": "git"
},
{
"status": "affected",
"version": "b3b94faa5fe5968827ba0640ee9fba4b3e7f736e",
"lessThan": "8b6534c9ae9dba5489703a19d8ba6c8f2cfa33c2",
"versionType": "git"
},
{
"status": "affected",
"version": "b3b94faa5fe5968827ba0640ee9fba4b3e7f736e",
"lessThan": "5fa30be7ba81191b0a0c7239a89befc0c94286d5",
"versionType": "git"
},
{
"status": "affected",
"version": "b3b94faa5fe5968827ba0640ee9fba4b3e7f736e",
"lessThan": "28275a7c84d21c55ab3282d897f284d8d527173c",
"versionType": "git"
},
{
"status": "affected",
"version": "b3b94faa5fe5968827ba0640ee9fba4b3e7f736e",
"lessThan": "16670534c7cff1acd918a6a5ec751b14e7436b76",
"versionType": "git"
},
{
"status": "affected",
"version": "b3b94faa5fe5968827ba0640ee9fba4b3e7f736e",
"lessThan": "670f8ce56dd0632dc29a0322e188cc73ce3c6b92",
"versionType": "git"
}
],
"programFiles": [
"fs/gfs2/ops_fstype.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.19"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.19",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "4.9.334",
"versionType": "semver",
"lessThanOrEqual": "4.9.*"
},
{
"status": "unaffected",
"version": "4.14.300",
"versionType": "semver",
"lessThanOrEqual": "4.14.*"
},
{
"status": "unaffected",
"version": "4.19.267",
"versionType": "semver",
"lessThanOrEqual": "4.19.*"
},
{
"status": "unaffected",
"version": "5.4.225",
"versionType": "semver",
"lessThanOrEqual": "5.4.*"
},
{
"status": "unaffected",
"version": "5.10.156",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.80",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.0.10",
"versionType": "semver",
"lessThanOrEqual": "6.0.*"
},
{
"status": "unaffected",
"version": "6.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/gfs2/ops_fstype.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-05-01T15:15:59.710",
"references": [
{
"url": "https://git.kernel.org/stable/c/15c83fa0fd659dd9fbdc940a560b61236e876a80",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/16670534c7cff1acd918a6a5ec751b14e7436b76",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/1ad197097343568066a8ffaa27ee7d0ae6d9f476",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/28275a7c84d21c55ab3282d897f284d8d527173c",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/5fa30be7ba81191b0a0c7239a89befc0c94286d5",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/670f8ce56dd0632dc29a0322e188cc73ce3c6b92",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8b6534c9ae9dba5489703a19d8ba6c8f2cfa33c2",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d6b1e8ea6f3418c3b461ad5a35cdc93c996b2c87",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ngfs2: Check sb_bsize_shift after reading superblock\n\nFuzzers like to scribble over sb_bsize_shift but in reality it's very\nunlikely that this field would be corrupted on its own. Nevertheless it\nshould be checked to avoid the possibility of messy mount errors due to\nbad calculations. It's always a fixed value based on the block size so\nwe can just check that it's the expected value.\n\nTested with:\n\n mkfs.gfs2 -O -p lock_nolock /dev/vdb\n for i in 0 -1 64 65 32 33; do\n gfs2_edit -p sb field sb_bsize_shift $i /dev/vdb\n mount /dev/vdb /mnt/test && umount /mnt/test\n done\n\nBefore this patch we get a withdraw after\n\n[ 76.413681] gfs2: fsid=loop0.0: fatal: invalid metadata block\n[ 76.413681] bh = 19 (type: exp=5, found=4)\n[ 76.413681] function = gfs2_meta_buffer, file = fs/gfs2/meta_io.c, line = 492\n\nand with UBSAN configured we also get complaints like\n\n[ 76.373395] UBSAN: shift-out-of-bounds in fs/gfs2/ops_fstype.c:295:19\n[ 76.373815] shift exponent 4294967287 is too large for 64-bit type 'long unsigned int'\n\nAfter the patch, these complaints don't appear, mount fails immediately\nand we get an explanation in dmesg."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: gfs2: Comprobación de sb_bsize_shift tras leer el superbloque. A los fuzzers les gusta manipular sb_bsize_shift, pero en realidad es muy improbable que este campo se corrompa por sí solo. Sin embargo, conviene comprobarlo para evitar errores de montaje problemáticos debido a cálculos erróneos. Siempre es un valor fijo basado en el tamaño del bloque, por lo que podemos comprobar que sea el valor esperado. Probado con: mkfs.gfs2 -O -p lock_nolock /dev/vdb for i in 0 -1 64 65 32 33; Antes de este parche obtenemos una retirada después de [ 76.413681] gfs2: fsid=loop0.0: fatal: bloque de metadatos no válido [ 76.413681] bh = 19 (tipo: exp=5, encontrado=4) [ 76.413681] función = gfs2_meta_buffer, archivo = fs/gfs2/meta_io.c, línea = 492 y con UBSAN configurado también obtenemos quejas como [ 76.373395] UBSAN: cambio fuera de los límites en fs/gfs2/ops_fstype.c:295:19 [ 76.373815] cambio El exponente 4294967287 es demasiado grande para el tipo de 64 bits 'long unsigned int'. Después del parche, estas quejas no aparecen, el montaje falla inmediatamente y obtenemos una explicación en dmesg."
}
],
"lastModified": "2026-06-17T05:19:06.193",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "65416FEB-3A76-4DA9-A96A-1479EC77AFB6",
"versionEndExcluding": "4.9.334"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "424802D2-E9E7-48A9-AD6F-DF2227B3D83A",
"versionEndExcluding": "4.14.300",
"versionStartIncluding": "4.10"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "A5C69A12-68E2-400E-9A5A-375A673C8402",
"versionEndExcluding": "4.19.267",
"versionStartIncluding": "4.15"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "94D21814-3051-4860-AB06-C7880A3D4933",
"versionEndExcluding": "5.4.225",
"versionStartIncluding": "4.20"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E2152F3D-E6D3-405D-B0BE-911B8B6E2EE6",
"versionEndExcluding": "5.10.156",
"versionStartIncluding": "5.5"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "51BBEF3B-79F5-4D4C-ADBA-F34DA0E2465C",
"versionEndExcluding": "5.15.80",
"versionStartIncluding": "5.11"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "64F9ADD1-3ADB-4D66-A00F-4A83010B05F0",
"versionEndExcluding": "6.0.10",
"versionStartIncluding": "5.16"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}